Apparatus for the prevention of fire by back firing in internal combustion engines, and for preventing the obstruction of the suction conduits by frost



c. H. BICHLER 1,870,486 APPARATUS FOR THE PREVENTION OF FIRE BY BACK FIRING IN Aug. 9, 1932.

INTERNAL COMBUSTION ENGINES, AND FOR PREVENTING THE DESTRUCTION OF THE SUCTION CONDUITS BY FROST Filed Jan. 8, 1950 3 Sheets-Sheet 1 J1 1 622731 (l arles EnrzLBiclzZer Aug. 9, 1932. C L 1,870,486

APPARATUS FOR THE PREVENTION OF FIRE BY BACK FIRING IN INTERNAL COMBUSTION ENGINES, AND FOR PREVENTINE'THE OBSTRUCTION OF THE SUCTION CONDUITS BY FROST Filed Jan. 8, 1930 3 shee ts-fiheet 2 Fig. 5

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(24371 5 iinrz' 31J0r Aug. 9, 1932. Q BICHLER 1,870,486

APPARATUS FOR THE PREVENTION OF FIRE BY BACK FIRING IN INTERNAL COMBUSTION ENGINES, AND FoR PREVENTING THE OBSTRUCTION OF THE SUCTION CONDUITS BY FROST Filed Jan. 8, 1950 3 Sheets$heet 5 Figl V/l/JE 1711/1.

Fig. 8

Patented Aug. 9, 1932 UNITED STATES PATENT OFFICE CHARLES HENRI BICHLER, F PARIS, FRANCE 7 APPARATUS FOR THE PREVENTION OF FIRE BY BAGK FIRING IN INTERNAL COMBUS- TION ENGINES, AND FOR PREVENTING THE DESTRUCTION OF THE SUCTION CON- DUITS BY FROST Application filed January 8, 1930, Serial No. 419,402, and in France August 2, 1929- the engine, extinguishing elements or groups of elements, which in order to afford the proper efiiciency, that is, a suitable cooling surface, comprise cooling elements having between them small-sized channels. Due to the small size of such channels, these are readily obstructed by the frost occasioned by the cooling due to the suction of the engine in certain conditions.

The present invention has for its object to 'i provide efiicient and novel arrangements which prevent all danger of fire due to backfiring, and also prevent all obstruction of the apparatus by frost, and it consists in providing exclusively in the central or axial part of the suction conduit of an internal combustion engine, suitable devices for stopping the flaming gas proceeding from the engine, while maintaining constantly free for the feeding of the engine, the annular or peripheral part of the conduit, thus assuring the normal functioning of the engine even in case of frost, and also preventing all danger of the.

According to the invention, the apparatus comprises solely, in the central part of the admission conduit of the engine and preferably in front of the carburetter, or even in the rear of the same, a central or axial chamher or well, adapted to receive the flaming gas and comprising a bottom part which consists of sets of plates, or comprises narrow channels, passages or orifices, for the circulation of the exhaust gas after it has been exti uished, and the annular re ion between said chamber or well and the wall of the admission conduit is provided with partitions, screens, or like parts preferably parallel to the said chamber and forming additional cooling surfaces; but these parts are so spaced that the channels thus formed will. have asutficient size to prevent theirohstruction by frost, thus assuring the normal functioning of the engine in all conditions, risks of fire being also prevented.

The accompanyingdrawings show various embodiments of the invention, adapted for use with aircraft engines.

Figs. 1 and 2 are respectively an axial sec.- tion and an end view of a tubular conduit pro, vided with a combined device according to the invention, whereby all back-fire and formation of frost will be prevented,

Figs. 3 and 4 are like views of a modification,

Figs. 5 and 6 are lengthwise sections showing other construction,

Figs. 7 and 8 show modified apparatus.

In the construction shown in Figs. 1 and 2, in the interior of the conduit 1 leading to the suction conduit 2 of the carburettor, not shown, and adapted to supply said carburetter with atmospheric air, there is disposed at a suitable point at the middle of said conduit a flame-protecting screen 3 of suitable disposition provided at the end of a conduit or tubular chamber 4. Said conduit or chamber, which is coaxial with the conduit 1, is supported by intermediate partitions .5 suitably spaced apart at a greater distance than the spacing of the elements of the said flame protecting screen 3, thus forming channels of such section that they Will not be easily obstructed by frost, and which are secured in a suitable manner to the conduit 1.

As shown in Fig. 1, the partitions 5 are suitably disposed in the form of steps, thus constituting a sort of funnel leading to the conduit 4 carrying the screen "3.

The operation is as follows:

During the normal operation of the engine, the suction of the air, which is effected through the carburettor, is produced upon the whole of the conduit 1. Should the flame-protecting screen be obstructed by reason .of frost, the cross section of the conduit 1 remaining available through the spaces between the partitions 5 {for the flow of ail, will be suirficient to assure the proper feed of the carburetter, so that the engine will operate normally, even should the said screen be obstructed by the frost.

If for any reason there is back fire to the suction end, the flaming gas in the conduit 1 circulating contrary to the arrows (Figure 1) and in the central or axial part of said conduit, will engage in the conduit or chamber 4, and the said screen 3 will prevent the flames from issuing from the apparatus,

whereby all danger of fire will be obviated.

Due to the disposition of the said screen 3 at a point relatively distant from the engine, it will be unaffected by the radiation from the engine, and said screen 3 accordingly will be maintained at a low temperature, thus expediting the extinction of the flames and preventing them from issuing from the conuit 1.

As above stated, the flaming gas which travels at great speed, will circulate almost entirely in the central part of the conduits in which the back firing takes place. chamber 4 will thus receive substantially the whole of the flaming gas in case of back fire, but should such flames rise above the chamher 4, the gas which is in small quantity and makes contact with the intermediate partition 5, will thus be extinguished by these latter.

In the construction shown in Figures 1 and 2, the conduit 1 has a rectangular section, as also has the screen 3, and said screen may as shown in Fig. 2 extend diametrically across the rectangular conduit 1, leaving at its opposite sides double conduits of adequate cross section. Such elements may have any suitable form, and may be held in position by rivets, cross pieces, or the like.

In the construction shown in Figs. 3 and 4, the conduit 1 has a circular cross section as well as the chamber 4, and the latter is secured to the conduit 1 by cross rivets 6 which also hold the concentric tubes 7 serving as the intermediate partitions 5 of Fig. 1.

In the two devices shown in Figs. 1 and 3, the intermediate partitions between the conduit 1 and the chamber or conduit 4 are suitably set back so as to form a sort of funnel which serves to guide the flames towards the extinguishing conduit 4.

In the device shown in Fig. 5, the conduit 4is terminated at the top part, which is I turned towards the suction tube 2 of the carburetter, by a sort of funnel 8 serving to conduct, to the extinguishing conduit 4,. the flaming gas which may proceed backwards, and said conduit 4 is surrounded by concentric partitions 9 disposed in a horizontal row.

It is possible to dispose between the conduit or chamber 4 and the conduit 1, annular bafiles 1()11 secured alternately to the conduit 1 and to the outer wall of the conduit 4, said baflles having at the bottom the outlet orifices 12 of suitable size and disposition.

Such bafiies, partitions or like parts dis- The said disposition, thus disposing the screen. 3.

next the suction tube 2 of the carburettor, not shown. The device consisting of the screen 3, its conduit 4, and the partitions or conduits 5, 7 or 9 might be disposed between the carburettor and the engine or at any other point in the admission conduit.

In the device shown in Fig. 7, the concentric'partitions are disposed around the nozzle 13 of the carburetter 14, and the nozzle is' disposed in the chamber 4 having at its lower part the flame screen 3.

For the use of the invention with engines employing a plurality of carburetters, con-' nection will be made between the feeding conduits 15 leading from the carburetters 14, by an equilibrating tube 16 disposed in front of the manifolds 17+18, and preferably in front-- of the said conduits 15.

This equilibrating connection may be rovided irrespectively of the disposition of the said conduits 15 with reference to the carburetters.

In the various forms of construction, the device can be disposed in front or at the rear of the carburetter, and the annular extinguishing strips, plates or partitions may consist of any suitable material, of any size as may be desired for various uses.

The invention is applicable to internal combustion engines of all classes, and for all uses, regardless of the size of the engine and its speed. According to the disposition of the carburetters and their air inletconduit, it is obviously feasible to modi the form and disposition of the conduits s own in the accompanying drawings in such manner as to obtain the best functioning while arresting all of the back fire in an effective manner and alsopreventing the obstruction of the admission conduit by the formation of frost in the said conduit.

What I claim is:

1. Apparatus for preventing back firing to the carburetters of internal combustion engines and for preventing obstruction of the suction conduits thereof by frost comprising a conduit adapted for connection with the carburetter, a tubular chamber located within said conduit in co-axial relation therewith, a foraminated fire stop located in obstructing relation to said chamber, and means between said chamber and conduit arranged to form interior passages of greater cross-section than the dimensions of the foramina of said fire stop, for maintaining those portions of the conduit at opposite ends of said chamber in open communication with each other.

2. Apparatus according to claim 1 wherein the interior passages are formed by spaced partitions extending lengthwise and externally of said chamber.

3. Apparatus according to claim 1 wherein the interior passages are formed by spaced partitions extending lengthwise and externally of said chamber in stepped relation whereby the terminal ends of said partitions 1gorm a funnel converging toward said cham- 4. Apparatus for preventing back firing to the carburetters of internal combustion engines and for preventing obstruction of the suction conduits thereof by frost comprising a conduit adapted for connection with the carburetter, a tubular chamber located within said conduit in co-axial relation therewith, a fire-screen extending diametrically across a restricted portion of said conduit at one end of said chamber, and spaced partitions arranged in honey-comb relation between said chamber and conduit to form interior passages of greater cross-section than the dimensions of the interstices of said screen, for maintaining those portions of the conduit at opposite ends of said chamber in open communication with each other.

5. Apparatus for preventing back firing to the carburetters of internal combustion engines and for preventing obstruction of the suction conduits thereof by frost comprising a circular conduit adapted for connection with the carburetter, a tubular chamber of circular cross-section located concentrically within said conduit, a fire screen located in obstructing relation to said chamber, and a plurality of spaced circular partitions surrounding said chamber within said conduit to form a plurality of annular passages of greater cross section than the dimensions of the interstices of said screen, for maintaining those portions of the conduit at opposite ends of said chamber in open communication with each other.

6. Apparatus for preventing back firing to the carburetters of internal combustion engines and for preventing obstruction of the suction conduits thereof by frost comprising a conduit adapted for connection with the carburetter, a tubular chamber located witha in said conduit in co-axial relation therewith,

and having an outwardly flaring end portion, a fire screen at the opposite end of said chamber, and a plurality of spaced partitions between said chamber and conduit arranged to form interior passages of greater crosssection than the dimensions of the interstices of said fire screen, for maintaining those portions of the conduit at opposite ends of said chamber in open communication with each other.

7. Apparatus for preventing back firing to the carburetters of internal combustion engines and for preventing obstruction of the suction conduits thereof by frost comprising a conduit adapted for connection with the carburetter, a tubular chamber located within said conduit in co-aXial relation therewith, and having outwardly flaring end portions, a fire screen located within one of said flaring end portions, and a plurality of spaced partitions between said chamber and conduit arranged to form interior passages of greater cross-section than the dimensions of the interstices of said fire screen, for maintaining those portions of the conduit at opposite ends of said chamber in open communication with each other.

8. Apparatus for preventing back firing to the carburetters of internal combustion engines and for preventing obstruction of the suction conduits thereof by frost comprising a conduit adapt-ed for connection with the carburetter, a tubular chamber located within said conduit in co-aXial relation therewith, and having an outwardly flaring end portion, a fire screen at the opposite end of said chamber, and a plurality of oppositely inclined bafiies surrounding said chamber within said conduit to form interior passages of greater cross-section than the dimensions of the interstices of said fire screen, for maintaining those portions of the conduit at opposite ends of said chamber in open communication with each other.

9. The combination of a carburetter for an 100 internal combustion engine, a nozzle connected with said carburetter, means for preventing back firing to said carburetter and for preventing obstruction of the suction conduit thereof by frost, said means comprising a 105 conduit enclosing said nozzle, a tubular chamber located within said conduit in co-axial relation therewith and surrounding said nozzle,

a foraininated fire stop located at one end of said chamber and means between said chamher and conduit in registry with said nozzle arranged to form interior passages of greater cross-section than the dimensions of the foramina of said fire stop for maintaining an open communication through said conduit. 115

In testimony whereof I have hereunto set my hand at Paris this 23rd day of December,

CHARLES HENRI BICHLER. 

